Advancements in communication technologies have permitted the introduction of, and popularization of, new types of communication systems. As a result of such advancements, the rate of data transmission, and corresponding amount of data, permitted to be communicated in such communication systems, has increased.
A radio communication system is representative of a type of communication system which has benefited from advancements in communication technologies. A radio communication system inherently increases communication mobility as communication channels defined in such a system are formed of radio channels and do not require wireline connections for their formation. A radio communication system, however, typically is bandwidth-limited. That is to say, regulatory bodies which allocate usage of the electromagnetic spectrum allocate only a limited amount of the electromagnetic spectrum for communications in a particular radio communication system. Because the spectrum allocation for use by a particular system is limited, communication capacity increase of a radio communication system is limited by such allocation. Increase of the communication capacity of the radio communication system, therefore, is typically only possible if the efficiency by which the allocated spectrum is used is increased.
Digital communication techniques, for instance, provide a manner by which to increase the bandwidth efficiency of communications in a communication system. The use of digital communication techniques are particularly advantageously implemented in radio communication systems due to the particular need to efficiently utilize the spectrum allocated to such systems.
A cellular communication system is exemplary of a radio communication system. Cellular communication systems make relatively efficient use of the spectrum allocated thereto. Signals generated during operation of the cellular communication system are of relatively low power levels. Because of the use of low-power signals, the same channels can be reused throughout a cellular communication system according to a cell reuse plan. Concurrent use of the same channels is permitted according to the cell reuse plan, thereby to effectuate different and concurrent communications on the same channels at different locations throughout the area encompassed by the cellular communication system.
However, even with the relatively efficient utilization of the allocated spectrum, many cellular communication systems have been operated at their maximum capacities, particularly at certain times-of-day and within certain cells of the cellular communication system. Digital communication techniques have advantageously been utilized in cellular communication systems to increase the communication capacities of such systems. Increased communication capacity of both voice and non-voice information is generally provided as a result of use of such digital communication techniques.
When information is digitized pursuant to a digital communication technique, the digitized information can be formatted into packets of data to be transmitted in packet form as discrete packets. When information is communicated in the form of packets of data, a dedicated channel need not necessarily be allocated for the transmission of the data. Instead, a channel can be shared, used by a plurality of mobile stations.
GPRS (General Packet Radio Service) communications for a GSM (Global System for Mobile communications) is a packet data service which shall be available to subscribers of some GSM systems. Standard specifications promulgated by ETSI pertaining to GPRS communications define the communication protocols for communicating packet data in such a system.
Both real-time and non-real-time communications can be effectuated utilizing packet data transmissions, such as those provided pursuant to GPRS. When real-time data is communicated, the manner, e.g., the rate in which the packets of data are communicated is required to be controlled to ensure that the packets of data are transmitted in a manner to permit their delivery in a timely manner at a destination.
The standard relating to GPRS communications, for instance, sets forth a mode of operation and a signaling protocol between a mobile station and the network infrastructure pursuant to which the GPRS communications are effectuated. A mobile station, for instance, transmits packets of data during packet data communication operations according, and responsive, to such protocol. The ETSI GSM specifications define how the GPRS packets are transferred over the GSM radio interface between a mobile station and a base station. The ETSI GSM standards also define the GPRS network elements, interfaces between network elements, signaling procedures, and data transfer procedures between the mobile station and the network.
The GPRS services will be provided also in TIA/EIA-136 mobile communication networks. The GPRS over TIA/EIA-136 has been named GPRS-136. GPRS-136 is being standardized in TIA. The GPRS-136 will differ from the GSM GPRS mainly in the radio interface part. It is necessary to define in the TIA/EIA-136 standards how the GPRS data packets will be transferred over the TIA/EIA-136 radio interface. This radio interface differs from the GSM radio interface in for instance bandwidth and frame structure. Most other aspects, except the radio interface, will be the same in GPRS-136 as in GSM GPRS. This means mainly that the ETSI GSM specifications will define the signaling procedures, data transfer procedures and the network elements and interfaces also in GPRS-136. From the user point of view many of the same services will be available as in GSM GPRS.
The proposed standards pertaining to uplink transmissions, i.e., packet data communicated by a mobile station to the network infrastructure, contained in an existing GPRS-136 draft standard does not, however, provide for significant bit rate increases in uplink double and triple rate relative to full rate of operation. A significant problem which limits the bit rate increase in the double-rate and triple-rate modes of operation is due to the existing requirement that the same sub-channel be used for both the uplink transmission of packet data and downlink acknowledgment of receipt of each packet of data. Namely, a PCF sub-channel is utilized by the network infrastructure to transmit acknowledgment indications responsive to receipt, at the network infrastructure, of GPRS 136 MAC PDUs on the same sub-channel. Such PCF sub-channel is also utilized by the network infrastructure to allocate uplink time-slots to the mobile station to communicate the packets of data thereon.
In other words, in the existing draft standard, a mobile station is required both to receive and to transmit upon the same sub-channel. But operation of the mobile station at a double or triple-rate of operation, would require full-duplex operation of the mobile station. Full-duplex operation would require more complex and costly implementation of the radio frequency circuitry of the mobile terminal.
A manner by which to permit double- or triple-rate communication of the packet data while permitting the mobile station to operate in a half-duplex mode would therefore be advantageous.
It is in light of this background information related to the communication of packet data that the significant improvements of the present invention have evolved.